Soundguy
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- Mar 11, 2002
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- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Re: [b]8N Capacitor Questions[/b]
I view 8v batteries in 6v systems as horrible bandaids, if done incorrectly. Usually you get an 8v battery that is undercharged.. or if you can tewak the charging system to run it.. you get reduced life on the lamps, and more primary coil current. In the case of ford frontmount tractors, if you are running an 8v system, my recomendation is to get one of the new 12v coils, and run that coil, with no other resistance.. ont he 8v setup... probably work fine. Those front mount 12v coil generally need 1/2 ohm of resistance inline with them to run on a 124v system.. but on the 9-10v system they are just about right. have to remove the ballast resistor as well.
as for caps and voltage rating.. capacity of the cap will make more of a difference than the working votlage, compaired to the max voltage. Max voltage on those automotive caps will be in the neighborhood of 60-120-200vdc. If a cap had a working voltage of 6v.. it should still be suitable for 12v apps. All my tractors that were 6v that have been converted to 12v are still running the same caps that come in the 6v tune up kits.
For round coil sidemount system that were designed for 6v, and run on 8v.. I think I'd expirement with a little inline resistance.. probably in .1 - .6 ohm range, and see what I could do about points life, vs spark quality. Ventalated points, if available, can help too.
As for time on, with ignition not running.. I wouldn't want any. When the ignition engine is off.. turn off the key. Obviously a few seconds / minutes won't hurt. but remember the contact surface are of the points is small, and they are conducting up to 4a.. and that will start heating the primary of the coil. These are meant for duty cycle.. not steady state...
Soundguy
I view 8v batteries in 6v systems as horrible bandaids, if done incorrectly. Usually you get an 8v battery that is undercharged.. or if you can tewak the charging system to run it.. you get reduced life on the lamps, and more primary coil current. In the case of ford frontmount tractors, if you are running an 8v system, my recomendation is to get one of the new 12v coils, and run that coil, with no other resistance.. ont he 8v setup... probably work fine. Those front mount 12v coil generally need 1/2 ohm of resistance inline with them to run on a 124v system.. but on the 9-10v system they are just about right. have to remove the ballast resistor as well.
as for caps and voltage rating.. capacity of the cap will make more of a difference than the working votlage, compaired to the max voltage. Max voltage on those automotive caps will be in the neighborhood of 60-120-200vdc. If a cap had a working voltage of 6v.. it should still be suitable for 12v apps. All my tractors that were 6v that have been converted to 12v are still running the same caps that come in the 6v tune up kits.
For round coil sidemount system that were designed for 6v, and run on 8v.. I think I'd expirement with a little inline resistance.. probably in .1 - .6 ohm range, and see what I could do about points life, vs spark quality. Ventalated points, if available, can help too.
As for time on, with ignition not running.. I wouldn't want any. When the ignition engine is off.. turn off the key. Obviously a few seconds / minutes won't hurt. but remember the contact surface are of the points is small, and they are conducting up to 4a.. and that will start heating the primary of the coil. These are meant for duty cycle.. not steady state...
Soundguy